1. Field of the Invention
The present invention relates to a turntable assembly of a spindle motor.
2. Description of the Related Art
Prevalent examples of recording media that write and read images, sounds, and other types of data at high density include optical discs, hard discs, cards, and tapes; and of these, optical discs are at the forefront of the mainstream.
The field of optical discs includes read only memory (ROM) products ranging from laser discs (LD) and compact discs (CD) to digital versatile discs (DVD).
Optical discs can be generally categorized into CDs and DVDs; CDs can be divided into CD-read only memory (CD-ROM) and CD-Rewritable (CD-RW); and DVDs can be split into DVD-ROMs and DVD-random access memory (RAM).
Such optical discs have tracks formed to spiral outward from the middle, whereon digital data of a predetermined format is written.
An optical disc apparatus for reading optical discs has a built-in spindle motor that spins an optical disc at high speed. The optical disc apparatus also includes a built-in actuator, which has a laser diode, lens, beam splitter, photodetector, and other installed optical devices.
The spindle motor has a turntable, and the turntable has bosses formed thereon. A back yoke passes through the bosses. After the back yoke passes through the bosses, the back yoke and the bosses are stuck together so that the back yoke is fixed on the turntable.
However, the method (according to the related art) of fixing the back yoke by sticking it to the bosses formed on the turntable employs excessive adhering force, which can damage the bosses.
Such damage to the bosses reduces the adhering force of the back yoke. If the adhering force of the back yoke is reduced, the back yoke disengages from the table, and is likely to cause a malfunction or failure of the spindle motor.
Furthermore, the method of adhering the bosses to the turntable results in unevenness of the adhered bosses. Under these conditions, maintenance is not easy.